Santa Ana winds will make a return to the region today, combining with low humidity levels to create dangerous fire conditions that are expected to continue into Thursday and bring the potential for power shutoffs.
A red flag warning of severe wildfire threat will take effect at 8 a.m. Wednesday for San Diego County inland valleys and mountains. The warning will remain in place until noon Thursday.
Forecasters said affected areas will see east to northeast winds of 15 to 25 mph, with some areas expected to get hit with gusts of 50 to 60 mph, with humidity dropping to between 7 and 12%.
"The winds will peak tomorrow (Wednesday) night, then weaken on Thursday," according to the National Weather Service. "The very low relative humidity and strong easterly winds will create critical fire weather conditions inland through Thursday morning, before winds weaken and humidity increases.
"Humidity will surge over the higher terrain on Thursday, and there may even be some light precipitation. Fair, with lighter winds on Friday, then increasing onshore flow will build the marine layer over the weekend ahead of a winter storm system slated to bring widespread wetting rain and mountain snow by Monday."
According to forecasters, the red flag warning means there is a potential for rapid fire spread should a blaze erupt, along with "extreme fire behavior."
San Diego Gas & Electric has notified about 31,000 customers of the potential for public safety power shutoffs due to the red flag conditions.
"Public safety power shutoffs are a last resort to protect public safety and reduce wildfire risk, and our employees are dedicated to doing everything we can to minimize impacts should it come to that," said Scott Crider, chief SDG&E customer officer.
"We understand the last thing our customers want to hear is that they may lose power given the holiday and COVID pandemic. Our meteorology team is closely monitoring the weather circuit by circuit, and it is our hope that Mother Nature will cooperate and conditions will change, eliminating or reducing the need for safety power shutoffs. But we must make sure our customers are prepared."
The power shutoffs could happen on Wednesday and potentially last into Friday morning depending on weather conditions and potential damage to the electric system, according to the utility, which noted that crews must inspect equipment during daylight hours to ensure power can be restored safely.
Visit sdge.com/ready to see a map and a list of communities that could be affected.
